Establishing regions of interest of the lower leg and ankle for perioperative volumetric assessment with a portable 3D scanner in orthopedic and trauma surgery - a pilot study.

BACKGROUND: Soft tissue swelling assessment benefits from a reproducible and easy to use measurement method. Monitoring of the injured lower extremity is of clinical import during staged soft tissue management. Portable 3D scanners offer a novel and precise option to quantify and contrast the shapes and volumes of the injured and contralateral uninjured limbs. This study determined three regions of interest (ROI) within the lower extremity (lower leg, ankle and foot), that can be used to evaluate 3D volumetric assessment for staged soft tissue management in orthopedic and trauma surgery. METHODS: Twelve healthy volunteers (24 legs) were included in this cohort study. Scans of all three ROI were recorded with a portable 3D scanner (Artec, 3D scanner EVA) and compared between the right and left leg using the software Artec Studio (Arctec Group, Luxemburg). RESULTS: Mean volume of the right leg was 1926.64 ± 308.84 ml (mean ± SD). ROI: lower leg: 931.86 ± 236.15 ml; ankle: 201.56 ± 27.88 ml; foot: 793.21 ± 112.28 ml. Mean volume of the left leg was 1937.73 ± 329.51 ml. ROI: lower leg: 933.59 ± 251.12 ml; ankle: 201.53 ± 25.54 ml; foot: 802.62 ± 124.83 ml. There was no significant difference of the overall volume between right and left leg (p > 0.05; overall volume: △ difference: 29.5 ± 7.29 ml, p = 0.8; lower leg: △ difference: 21.5 ± 6.39 ml, p = 0.8; ankle: △ difference: 5.3 ± 2.11 ml, p = 0.4; △ difference: 16.33 ± 4.45 ml, p = 0.8. CONCLUSION: This pilot study defines three regions of interest of the lower leg and demonstrates no difference between the right and left side. Based on these ROI, further studies are needed to evaluate the clinical applicability of the scanner.

Volumetry of Hand and Forearm: A 3D Volumetric Approach.

BACKGROUND: Swelling and edema of the hand and forearm may occur in various traumatic and degenerative diseases. So far, no precise measurement protocol exists. The objective of this study was to evaluate an examination protocol with relevant regions of interest (ROIs) measured by a 3-dimensional (3D) scanner to achieve precise, reproducible, and objective measurements for an optimized detection of volumes of the hand and forearm. METHODS: A 3D scan protocol was developed using an Artec, 3D scanner EVA to measure discrete hand volumes of healthy volunteers. Five areas were defined as ROIs, representing volumes of the finger, metacarpus, wrist, hand, and distal forearm. Contralateral limbs were used for volume comparisons and calculation of volume differences. RESULTS: For this study, 12 individuals (58.3% women, 24 hands and forearms) with a mean age of 27.1 ± 3 years were included. Mean volume values for left and right ROIs correlated with each other, with slightly higher volumes for the right upper extremity. Volume differences showed statistically significant results for the finger region (ROI I; P = .009), the metacarpal region (ROI II; P < .001), hand region (ROI IV; P = .001), and forearm region (ROI V; P = .006), with the exception of the wrist region (ROI III; P = .722). CONCLUSIONS: Our results demonstrate that this 3D volumetric approach is a reliable and objective tool for measuring volumes and circumferences in hand and forearm. Based on our determined ROIs, further studies are needed to explore the significance for clinical applications.

Evaluation of the accuracy of a mobile and a stationary system for three-dimensional facial scanning.

PURPOSE: Numerous three-dimensional (3D) facial scanners have emerged on the market; however, publications evaluating their accuracies are sparse. In this study, the accuracy of two 3D scanners used in facial scanning was evaluated. MATERIALS AND METHODS: A test specimen was attached at the right cheek and the forehead of 41 volunteers. These volunteers were scanned with Artec EVA® and FaceScan3D®. The acquired data were aligned to a 3D model of the test specimen for comparing the mean error, original length and width and angles to the measured values. RESULTS: The mean error in Best Fit alignment is significantly lower using Artec EVA (p < 0.001) for both test specimens. The deviation from the original length and width is significantly lower for the test specimens (p < 0.01) when measured with Artec EVA. The aberration of the angles measured between the front plane and the side plane is significantly lower when measured with Artec EVA (p < 0.001). Captured with Artec EVA the discrepancy between the original angle and the angle measured between the side planes to each other is significantly lower (p < 0.01). CONCLUSIONS: Scanning with Artec EVA leads to more accurate 3D models as compared to scanning with FaceScan3D. The exactness achieved by both scanners is comparable to other scanners mentioned in literature.